1. Field of the Invention
This invention relates to a cooling system for cooling a heat-generating element in electronic equipment, for example, and particularly to such system designed for enhancement of the rate of moisture adsorption as well as downsizing of the system.
2. The Prior Art
FIG. 1 illustrates the configuration of a cooling system which may be conceived from the prior art. By way of example, a component 10 being cooled may be a heat-generating semiconductor integrated circuit element mounted on a printed-circuit board and covered by a water jacket cover into and through which cooling liquid or coolant J is passed to cool the heat-generating element.
The component 10 being cooled is chilled by the coolant supplied by a coolant circulating system 20. In the coolant circulating system 20, the coolant J from a coolant storage tank 22 is supplied by a pump 23 into a moisture eliminating filter 24 from where the coolant having moisture removed therefrom is passed through a supply piping 27 having a moisture detecting sensor 25 disposed therein into a water jacket cover (not shown) around the component 10 being cooled. The coolant having flowed through the jacket cover is then passed through a return piping 26 back to the coolant circulating system 20 where it is chilled through a heat exchanger 21 prior to being returned to the coolant storage tank 22. The moisture detecting sensor 25 comprises a pair of electrodes disposed in the piping 27, the arrangement being such that upon moisture depositing between the pair of electrodes, a contact signal will be generated.
The heat exchanger 21, coolant storage tank 22, pump 23, moisture eliminating filter 24 and moisture detecting sensor 25 are successively connected by the pipings 26 and 27 to constitute a circulating fluid circuit. Through this fluid circuit is circulated an insulating coolant such as perfluorocarbon so that the heat produced in the component 10 being cooled is dissipated through the heat exchanger 21 to the atmosphere to thereby suppress a rise in temperature in the component 10.
Where the component 10 being cooled is a semiconductor integrated circuit element as exemplified above, the cooling liquid is flowed in direct contact with the semiconductor integrated circuit element. It is for this reason that the coolant must be an insulating coolant. Should moisture be entrained in the coolant, the moisture would possibly create the risk of an accidental short-circuit between the terminals of the semiconductor integrated circuit element.
In order to avoid such situation, it is conceivable to dispose the moisture eliminating filter 24 which may comprise zeolite-based adsorbent, for example in the coolant circulating circuit so that any moisture entrained in the coolant may be adsorbed by the moisture eliminating filter 24 to prevent ingress of moisture into the component 10 being cooled. In addition, it is preferable that the moisture detecting sensor 25 be located adjacent the coolant inlet to the component 10 through which the coolant from the circulating circuit is introduced into the component 10 and that a function be added for generating an alarm to indicate instantly when any moisture is trapped in the coolant before flowing into the component 10.
As discussed above, since the moisture eliminating filter 24 is for eliminating moisture contained in the coolant, all of the coolant to be supplied to the component 10 being cooled must be passed through the moisture eliminating filter 24.
In general, since the moisture eliminating filter 24 is contained in a relatively small-sized filter housing 24A, the filter is correspondingly small in size. While it is depicted in an exaggerated size in FIG. 1 for the benefit of illustrating the construction, the volume of the filter housing 24A is actually on the order of one-tenth of that of the coolant storage tank 22. The moisture eliminating filter 24 which is generally cylindrical in shape is configured such that as the coolant is introduced into the filter 24 via one end thereof and passed therethrough and exuded therefrom into the interior of the filter housing 24A, the moisture in the coolant is adsorbed by the filter. Flowing a large amount of coolant through the small-sized moisture eliminating filter 24 necessitates a higher flow rate, resulting undesirably in reducing the rate of moisture adsorption. In addition, an increase in the flow rate creates a greater pressure loss across the moisture eliminating filter 24, which in turn requires a larger capacity pump.
Furthermore, disposing the moisture eliminating filter 24 and the moisture detecting sensor 25 independently from each other in the circulating circuit imposes the disadvantage of oversizing the entire coolant circulating system 20.
Accordingly, it is an object of this invention to provide a cooling system which provides for downsizing of the system.
It is another object of this invention to provide a cooling system which allows for enhancing the rate of moisture adsorption.
According to this invention, the moisture eliminating filter is contained in the coolant storage tank. Specifically, the moisture eliminating filter is disposed in the coolant storage tank such that it covers an outlet from the tank. In an alternate embodiment, the moisture eliminating filter is located in the coolant storage tank with its outer periphery in contact with the inner periphery of the coolant storage tank.
It will thus be appreciated that this construction eliminates the need for provision of an outer filter housing, leading to downsizing of the system. Additionally, the coolant storage tank is increased in volume, which allows for a relatively lower flow rate of coolant as well as increasing the volume of the moisture eliminating filter, whereby the rate of moisture adsorption may be improved. It is thus to be understood that this construction introduces the additional advantage of providing a highly stable cooling system which does not permit moisture to migrate into a component being cooled.
Moreover, if the moisture detecting sensor is also disposed in the coolant storage tank, it contributes to further downsizing of the system.